Heinz Jakob

Detection of Central Pulmonary Artery Thromboemboli by Transesophageal Echocardiography in Patients with Severe Pulmonary Embolism

Transthoracic echocardiography generally provides only indirect signs of pulmonary embolism. In contrast, with transesophageal echocardiography the thromboembolus itself can be visualized in the central parts of the pulmonary artery. The aims of our study were to evaluate, first, the incidence of central pulmonary artery thromboemboli in patients with severe pulmonary embolism, and second, the accuracy of the echocardiographic diagnosis. Our study group comprised 60 patients with proved severe pulmonary embolism. All patients were examined by transthoracic and transesophageal echocardiography. The echocardiographic findings concerning the absence or presence of central pulmonary artery thromboemboli were compared with the results of different reference methods. Central pulmonary thromboemboli were found in 35 patients (58.3%) by echocardiography. Two types of thrombus were differentiated. Type A is a long, highly mobile thrombus, and type B is an immobile wall-adherent thrombus. In comparison with the reference methods, we determined a sensitivity of 96.7% and a specificity of 88% for the echocardiographic detection of central pulmonary artery thromboemboli in patients with severe pulmonary embolism. Transesophageal echocardiography seems to be a useful method for the diagnosis of severe pulmonary embolism. In our series, central pulmonary artery thromboemboli were present in more than half of the patients. In these cases, transesophageal echocardiography can clarify the diagnosis within a few minutes without further invasive diagnostic procedures.

Diagnosis of perioperative myocardial necrosis following coronary artery surgery ― a reappraisal of isoenzyme analysis

Although the routine determination of CK-MB activity is widely used after coronary artery bypass grafting (CABG), the diagnosis of a perioperative myocardial necrosis remains arbitrary. The intention of the present study was to develop discriminative enzymatic parameters of CK-MB activity in a collective of 710 patients following CABG. Patients were grouped according to their postoperative electrocardiogram (ECG). For each patient, the time activity curve of CK-MB was determined. The total amount of CK-MB was calculated by integrating the area beneath the CK-MB activity curve. Patients presenting with an unchanged postoperative ECG (group I) or a new bundle branch block with uncompromised haemodynamics (group IIa) had an uniform and low profile of CK-MB activity. Serial CK-MB activities as well as the integrated CK-MB area of these two collectives were significantly different (P less than 0.001) from values determined for patients with bundle branch block and low cardiac output (group II b) or patients with new Q waves (group III). After 24h, the 90th percentile of serial CK-MB activities of group I had declined to 18 U/l and was clearly exceeded by 90% of all patients that belonged to either group IIb or III. The 90th percentile of CK-MB areas for group I showed a value of 801 U/l x h. CK-MB areas above 801 U/l x h were seen in about 50% of all patients of group IIa.(ABSTRACT TRUNCATED AT 250 WORDS)

Resection of central primary pulmonary artery sarcoma

Primary sarcomas of the pulmonary arteries are rare, and the diagnosis is in the majority of the reported cases established postmortem. Surgical resection of these centrally located tumors has been performed either by pneumonectomy and/or local tumor resection. We report on two patients with sarcomas of the central pulmonary arteries who underwent successful resection of the tumor and prosthetic replacement of the arteries under cardiopulmonary bypass. One patient required additional thromboendarterectomy of the right pulmonary artery branches because of secondary thrombus formation. As primary pulmonary artery sarcomas are refractory to both chemotherapy and radiation, surgical resection remains the only means of treatment. The prognosis depends entirely upon resectability, which, if necessary, should be performed with the aid of cardiopulmonary bypass. In this way, lung resection may be avoided.

Influence of incremental preoperative risk factors on the perioperative outcome of patients undergoing emergency versus urgent coronary artery bypass grafting.

A retrospective analysis of 127 patients with impending myocardial infarction undergoing coronary artery bypass grafting was performed to evaluate incremental risk factors associated with perioperative mortality and morbidity. Fifty-four patients (group 1) were operated upon as emergencies within 24 h and 73 patients underwent urgent coronary revascularization within a mean of 3.4 days (group II) after admission. The incidence of non-transmural myocardial infarctions (NTMI), haemodynamic parameters, the number of diseased vessels and the incidence of a preceding percutaneous coronary dilatation (PTCA) were not statistically different between the groups. The overall perioperative mortality was 8.7% (16.7% group I, 2.7% group II). Major non-fatal complications were frequent in the surviving collective including low cardiac output in 14 patients (12.1%) and transmural or subendocardial perioperative infarction in 12 patients (10.3%). Perioperative mortality was associated with reduced left ventricular myocardial function (P less than 0.001), operation within 24 hr after onset of anginal symptoms (P less than 0.001) or subendocardial infarction (P less than 0.025) in the 4 weeks before operation. Perioperative mortality was independent of the degree of coronary stenosis, number of distal anastomoses or performance of a coronary endarterectomy. Of the patients, 90.5% (87.5% of group I and 92.3% of group II) included in a mean follow-up of 16.8 months (range 5-27 months) were graded into Canadian Heart Functional Class I. Successful coronary surgery for acute myocardial ischaemia results in excellent late functional recovery. The major risk factors for fatal perioperative outcome are reduced left ventricular function and the necessity of every early surgical intervention.

Emergency surgical revascularization following coronary angioplasty: evaluation of operative results by isoenzyme analysis and electrocardiography

Seventeen patients underwent emergency coronary artery bypass grafting due to balloon catheter induced occlusion or dissection of a major coronary artery. Patients were revascularized within a maximum of 210 min from the onset of ischaemia and received an average of 1.6 distal anastomoses. A perioperative transmural or non-transmural myocardial infarction as diagnosed by CK-MB activity and electrocardiographic patterns occurred in 7 patients (41.2%). One early death resulted in an overall perioperative mortality of 5.9%. Successful preservation of myocardium was demonstrated in 10 patients by a rapid decline of CK-MB activity, no perioperative electrocardiographic changes and no requirement for inotropic support. The incidence of a perioperative myocardial infarction was independent of the anginal status before coronary angioplasty or the angiographic evidence of a complete occlusion versus a dissection. Major ischaemic myocardial complications associated with coronary angioplasty are rare but frequently catastrophic events. Fast surgical intervention is mandatory to prevent myocardial infarction or to limit the extent of injury. The operative outcome can be evaluated by careful analysis of time release curves and cumulative parameters of CK-MB activity.

Evaluation of the healing of precoated vascular dacron prostheses

ZusammenfassungGestrickte und gewebte Dacronprothesen mit kommerzieller Vorbeschichtung aus bovinem Kollagen, Gelatine oder humanem Albumin wurden bei 35 Schweinen End-zu-Seit zwischen infrarenaler Aorta und der Bifurkation implantiert. Die Prothesen wurden nach 4, 8 und 12 Wochen explantiert und mit 6 unbeschichteten gestrickten Dacronprothesen verglichen. Unbeschichtete Dacronprothesen entwickelten rasch eine fest haftende Neointima mit Endothelauskleidung, wobei die thrombusfreie Fläche gegenüber beschichteten Prothesen signifikant größer war (P<0,05). Die verlangsamte Albuminresorption führte zu einer verzögerten und inkompletten Neointimaausbildung sowie zu einer ausbleibenden Protheseneinheilung. Obwohl das bovine Kollagen nur schwach vernetzt war, war auch bei gewebten beschichteten Dacronprothesen die Neointimaausbildung verzögert, wobei noch nach 12 Wochen die Neointima nur locker mit der Prothese verbunden war. Das identische Kollagen sowie die bovine Gelatine waren bei gestrickter Prothesenstruktur bereits nach 4 Wochen resorbiert und die Prothesen waren komplett eingeheilt. Diese beiden Prothesentypen zeigten jedoch nach 8 bzw. 12 Wochen konstant einen organisierten thrombotischen Verschluß. Hier wies die Histologic eine Hyperplasie glatter Muskelzellen innerhalb der verdickten distalen Anastomosenregion nach. Diese Ergebnisse zeigen, daß die zeitgerechte Wiederkehr der Porosität unverzichtbar ist für die regelrechte Entwicklung sowie für die Aufrechterhaltung einer intakten Neointima. Hier sind sowohl die Struktur der Prothese als auch die Art der Beschichtungsverarbeitung entscheidende Parameter, die die Resorptionsrate der Imprdgnierung beeinflussen.SummaryKnitted and woven Dacron grafts commercially coated with bovine collagen, gelatin and human albumin were implanted end-to-side between the infrarenal aorta and the bifurcation in 35 growing pigs. Grafts were explanted after 4, 8 and 12 weeks and compared to 6 uncoated knitted prostheses preclotted with blood that served as a control. Uncoated grafts rapidly developed a firmly attached neointima lined with endothelium. Compared with coated grafts the thrombus-free area of uncoated grafts was significantly larger (P < 0.05). The slow resorption of albumin resulted in a delayed and incomplete neointimal healing and failing graft incorporation. Although the bovine collagen was only minimally cross-linked by formaldehyde, healing of the neointima was compromised in a thin woven graft that demonstrated peeling of the inner capsule even after 12 weeks. The identical collagen as well as bovine gelatin were quickly degraded in knitted grafts and both types showed transprosthetic infiltration at 4 weeks. All knitted grafts coated with either collagen or gelatin, however, were occluded after 8 and 12 weeks. Light microscopy revealed hyperplasia of smooth-muscle cells within the thickened distal anastomotic region. These results demonstrate that a timely return of porosity is mandatory for the development and maintenance of an intact neointima. Both the structure of the fabric as well as the method of preparing the coating are crucial variables to determine the rate of biodegradation.

Anästhesie bei transfemoraler und transapikaler Aortenklappenimplantation

ZusammenfassungTransfemorale (TF) und transapikale (TA) Aortenklappenimplantationen sind neue interventionelle Verfahren, die den Anästhesiologen allerdings oft vor größere Herausforderungen stellen als klassische Operationen unter kardiopulmonalem Bypass. Beim gegenwärtigen Indikationsspektrum handelt es sich nämlich um zumeist hochbetagte Patienten mit erheblicher Komorbidität, pulmonalvaskulärer Hypertonie und sehr hohem operativen Risiko.Art und Umfang individueller Komorbidität sind bei der Wahl des Anästhesieverfahrens (Intubationsanästhesie vs. Stand-by/Analgosedierung) ebenso wichtig wie interventionsphasenspezifische Kreislauftherapie und interdisziplinäre Kommunikation. Ein Allgemeinanästhesieverfahren auch bei der TFAortenklappenimplantation ist in vielerlei Hinsicht von Vorteil und scheint nicht zu schlechteren Ergebnissen zu führen. Aufgrund möglicher gravierender hämodynamischer Alterationen (kardiogener Schock, Koronarischämie, Arrhythmien) sowie interventioneller Komplikationen (Blutung, Ventrikelverletzung, Gefäßverletzung) verwenden die Autoren routinemäßig eine erweiterte invasive Kreislaufüberwachung. Postinterventionell wurde eine deutliche signifikante Zunahme des Herzindex, aber auch aller Füllungsdrücke beobachtet. Die periinterventionelle Anästhesiebindungszeit bei den ersten 100 Interventionen betrug 263 min (± 96) bei TF und 297 min (± 78) bei TA, erscheint damit eher höher als bei offener Aortenklappenimplantation, nahm jedoch bei TF im Verlauf signifikant ab.Entsprechend spielt der Anästhesiologe bei diesen sicher noch entwicklungsfähigen Verfahren eine wichtige Rolle für die invasive kardiopulmonale Überwachung, interventionsphasenorientierte kardiovaskuläre Pharmakotherapie sowie „troubleshooting“ bei Komplikationen.AbstractPercutaneous transfemoral and transapical aortic valve implantations are novel procedures that often confront the anesthesiologist with bigger challenges than surgical aortic valve replacements using cardiopulmonary bypass. Due to old age and the presence of severe comorbidities including pulmonary vascular hypertension, most patients have a very high risk.Individual comorbidities and their severity are as important for the choice of the anesthetic technique as pharmacological cardiovascular therapy and communication during the respective phases of the intervention. Since severe hemodynamic alterations (cardiogenic shock, coronary ischemia, arrhythmias) and potential interventional complications (bleeding, ventricular and vascular injury) may occur, the authors routinely perform an extended cardiovascular monitoring. General endotracheal anesthesia may be advantageous even for transfemoral valve implantation and was not associated with a worse outcome. Following valve implantation a substantial increase in cardiac index, but also of all filling pressures was measured. Anesthesia coverage time for the first 100 cases averaged 263 min (± 96) for transfemoral and 297 (± 78) for transapical valve implantation, which appears greater than for conventional aortic valve replacement surgery, but it decreased significantly for transfemoral valve implantation over the course of interventions.Accordingly, the anesthesiologist, besides providing anesthesia and managing the airway, assumes responsibility for invasive cardiopulmonary monitoring, cardiovascular pharmacotherapy tailored to intervention phases, and „troubleshooting“ in the event of complications for these still developing interventions.

Transcatheter Aortic Valve Implantation in Aortic Valve Regurgitation

Abstract Transcatheter aortic valve implantation (TAVI) has been initially considered as an alternative for high-risk patients with aortic stenosis. Although the current experience is limited, TAVI might be also an alternative to treat patients with pure, severe aortic regurgitation. The present article describes all currently available transcatheter aortic valves, which have been used (mainly off-label) in patients presenting with pure aortic regurgitation. Although the current experience is limited and larger multicenter studies or registries are warranted, the concept of TAVI in pure aortic regurgitation is feasible and might be an alternative option.

[Successful post-bypass extracorporeal circulatory assistance with the centrifugal pump].

SummaryPatients with reduced left ventricular function do have an increased risk of inability to be weaned off bypass after open heart surgery despite maximal pharmacologic support and intraaortic balloon counter-pulsation. Centrifugal pumps used for extracorporeal circulatory assist can maintain a patient in low cardiac output up to days without anticoagulation. We used a centrifugal pump in 3 patients: as a left ventricular assist device (LVAD) in 2 patients and right ventricular assist device (RVAD) in 1 patient. One LVAD-patient became a long-term survivor after 20 h of assist, another was bridged sucessfully to an open heart procedure for 2 h after papillary muscle rupture. One RVAD patient died on the operating table due to massive tracheal bleeding probably caused by pulmonary hypertension.ZusammenfassungPatienten mit stark eingeschränkter linksventriculärer Funktion sind bei einem Eingriff am offenen Herzen trotz maximaler pharmakologischer Unterstützung und intraaortaler Gegenpulsation gefährdet, nicht von der Herz-Lungenmaschine abgewöhnt werden zu können. Mit Hilfe von Zentrifugalpumpen kann eine extracorporale Kreislaufassistenz bis zu Tagen ohne Anticoagulation aufrecht erhalten werden. Wir setzten eine Zentrifugalpumpe bei 3 Patienten ein: Zweimal zur linksventriculären Assistenz und einmal zur rechtsventriculären Assistenz. Ein linksventriculär assistierter Patient wurde Langzeitüberlebender nach 20 h Assistenz, ein weiterer Patient nach Papillarmuskelabriss wurde erfolgreich bis zum Mitralklappenersatz über 2 h präoperativ assistiert, ein rechtsventriculär assistierter Patient verstarb jedoch auf dem Operationstisch bei massiver Trachealblutung, wahrscheinlich bedingt durch eine schwere pulmonale Hypertonie.Patients with reduced left ventricular function do have an increased risk of inability to be weaned off bypass after open heart surgery despite maximal pharmacologic support and intraaortic balloon counter-pulsation. Centrifugal pumps used for extracorporeal circulatory assist can maintain a patient in low cardiac output up to days without anticoagulation. We used a centrifugal pump in 3 patients: as a left ventricular assist device (LVAD) in 2 patients and right ventricular assist device (RVAD) in 1 patient. One LVAD-patient became a long-term survivor after 20 h of assist, another was bridged successfully to an open heart procedure for 2 h after papillary muscle rupture. One RVAD patient died on the operating table due to massive tracheal bleeding probably caused by pulmonary hypertension.